With the advancement of process technology, oxide thin film transistors (Oxide TFT) have been widely used in displays so as to adapt to requirements of thinness, miniaturization and the like for displays.
Oxide thin film transistor array substrate are widely applied in displays (such as liquid crystal displays), as shown in FIG. 1, an existing oxide TFT generally comprises: a substrate 1, a gate provided on the substrate 1, a gate insulation layer 3 covering the gate 2 and an exposed portion of the substrate 1 with respect to the gate 2, an oxide semiconductor active layer 4 provided on the gate insulation layer 3, a source and a drain 6 respectively connected to the oxide semiconductor active layer 4, and an etch stopping layer 5 provided between the source and the drain 6 above the oxide semiconductor active layer 4.
The oxide semiconductor active layer 4 is generally made of an oxide semiconductor material containing at least one element of indium, gallium and zinc, for example, indium gallium zinc oxide (IGTO). The source and the drain 6 is generally made of a metal material such as copper (Cu), titanium (Ti), molybdenum (Mo), an alloy thereof or the like. Inventors found that the metal atoms such as copper, titanium, molybdenum or the like in the material of the source and the drain 6 have poor bonding force, and can easily diffuse or result in electron transfer, and enter into the oxide semiconductor active layer 4 to combine with oxygen ions in the material of the oxide semiconductor active layer 4, thus destabilizing the oxide TFT.